Image capturing devices, such as cameras, tend to have a lens that focuses an image on an image sensor, such as film or a charge coupled device (CCD). Lens distortions, called aberrations, limit the sharpness of the image formed by the lens. These aberrations are intrinsic to the physics of optical image formation and will be present even if the lens has no physical imperfections (e.g., manufacturing flaws) and is perfectly focused. Generally, the more optical elements in a lens the smaller the aberrations, but each optical element adds additional cost. To reduce cost, especially in small format devices like cell phones, many cameras use lenses with significant artifacts and the image resolution is not limited by the image sensor but by the lens optics.